Ink web cassette for rotary printing system

ABSTRACT

A printing system, particularly adapted for clean, economic printing of small quantities with a minimum of makeready, employs a disposable ink web for providing a source of ink preworked to proper printing consistency. The ink web, which is an elongated strip of flexible material carrying preworked printing ink, is supplied in pre-inked form and is adapted to be mounted in the printing press and fed by the press drive in synchronism with the rotary motion of the plate cylinder for application of ink of proper printing consistency from successive portions of the web to the press plate throughout the length of the web. Preferably, the web is supplied in a disposable cassette which is releasably mounted in the press in connection to the drive thereof, and includes at least one opening for exposing portions of the web for inking of the press-plate.

[45] Nov. 27, 1973 United States Patent Bullock PAIENTEUNUYZYIQH u3.774.535 sum 1m e VENTOR. EDWA K. BULLOCK INH/@m mma.

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SHUQT 3 (if G INVENTOR EDWARD KBULLOCK a /l/J Bm y WMZ@ f/ 9m MM@ ATTORNE YS PAIENTED NUYZ'I ISH SHEU LL CF G FIG-4 INVENTOR. EDWARD K. BULLOCKY ATTORNEYS PMENTEU NM2? 8973 3,774,538

SHEET 6 GF G INVENTOR. FI G T EDWARD KBULLOCK AT TORN E YS INK WEBCASSETTE FOR ROTARY PRINTING SYSTEM BACKGROUNDOF THE INVENTION l. Fieldof the Invention The invention relates to a printing system and, moreparticularly, to a simplified lithographie printing system and methodemploying a disposable ink web and to an ink web cassette for the same.

2. Prior Art lt is often desirable to reproduce an image in relativelysmall quantities. For example, photographs produced from rapidprocessing or so-called selfdeveloping film materials of the typeinvolving a diffusion-transfer method of image-formation may be used asthe image carrier or so-called press-plate in a lithographic press toprovide printed reproductions of vthe image. However, printing by meansof a conventional lithographic press is generally a messy, untidyoperation which requires considerable makeready and startup operations,as well as constant attention by a highly skilled operator during theprinting run. Primarily, these difficulties are caused by a complicatedinking system in which ink is supplied to the press-plate from an inkfountain or the like through a plurality of milling and inking rolls,etc. Initially, the inking system is adjusted by the operator during atrial run to provide ink of proper printing consistency and not onlyrequires particular operative skill and experience, exceeding thecapabilities of the amateur, but also results in a relatively largenumber of initial prints of unsatisfactory quality so as to beexcessively wasteful in small production runs. Moreover, once properreproductions have been achieved, constant control of the inkingapparatus is required for the duration of the printing run.

Accordingly, it is an important object of this invention to provide aprinting system suitable for efficient operation by an amateur.

`Another object of this invention is to provide a printing system andmethod of printing requiring a minimum of makeready.

Still another object of this invention is to provide a printing systemhaving a clean, disposable source-of ink of proper printing consistency.

A further object of this invention is to provide a printing systememploying disposable inking material supplied in pre-inked form.

An additional object of this invention is to provide a unique inkstorage applicator system and method for proper, consistent'inking of apress-plate during a printing operation.

A still further object of this invention is to provide a disposablecassette for dispensing an ink web for use in a printing press.

A further object of this invention is to provide an efflcient method ofprinting.

SUMMARY OF THE INVENTION The invention concerns a press-plate printingsystem employing a disposable source and carrier including an ink webmade of elongated strip material carrying printing ink preprocessed toproper printing consistency. The system includes means for advancing theweb from a storage location into a given vlocation so as toprogressively present successive portions of the ink surface thereat,and means for transferring ink from the presented portions of the web tothe image carrier for inking thereof. Preferably, a nonskinning ink isemployed with a strip of flexible, substantially inelastic materialwhich, while wettable by the ink, is otherwise chemically inactivetherewith and substantially inpervious thereto such that the ink iscarrier as a thin coating on the strip surface.

In the illustrated embodiment, the web is supplied in pre-inked formwithin a disposable cassette which is adapted for web storage, plateinking, and web disposal. A pair of reels to which opposite ends of theweb are attached, are mounted within the cassette housing for rotationabout spaced parallel axes, and the web is initially coiled on one reeland extends across a passageway of the housing which permits incrementalsections of the web to be progressively exposed for inking of thepress-plate. Both reels are adapted to be externally driven such thatthe web may be reversibly transported across the passage-Hence, the webmay be driven in one direction for repeated inking of the pressplate andthen returned to the original spool for reuse or disposal. The web istightly wound on the reels so as to reduce drying and to provide inkreworking during winding and unwinding. Preferably, the cassette is asymmetrical unit which may be reversibly mounted in the printing pressfor plate inking from the opposite side of the web during rewind to thesupply reel, and the passageis configured to accept an inking pressureroller which supports the web portions exposed at the open end of thepassageway so as to provide pressure contact between these web portionsand the pressplate.V

In another embodiment, the cassette takes the form of a single spoolcannister from ywhich the web may be dispensed for inking purposes andthen returned for reuse and disposal.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features that are consideredcharacteristic of the invention are set forth with particularity in theappended claims. The invention itself, however, both as to itsorganization and its method of operation, together with additionalobjects and advantages thereof, will best be understood from thefollowing description of the preferred embodiment'when read'inconnection with the accompanying drawings wherein like numbers have beenemployed in the different figures to denote the same parts and wherein:

FIG. l is a diagrammatic view in perspective of a compact printing pressembodying the features of this invention;

FIG. 2 is a plan view of the printing press of FIG. l;

FIG. 3 is a view in elevation of the press of FIG. l with the side wallpartly cut away to illustrate the ink web cassette and other components;

FIG. 4 is a view in perspective of the preferred embodiment of the inkweb cassette;

FIG. 5 is a view in section of the inking web utilized in the preferredembodiment;

FIG. 6 is a fragmentary view illustrating the clutch arrangement adaptedto drive the ink cassette;-

FIG. 7 is a fragmentary view illustrating the cassette releasemechanism;

FIG. 8 is a view in perspective of another embodiment of the inkcassette provided in accordance with the invention;

FIG. 9 is a fragmentary sectional view taken generally along line 9 9 ofFIG. 8; and

FIG. l() is a fragmentary sectional view taken along line 10-l0 of FIG.8.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIGS. l-3, theprinting system preferably takes the form of an offset printing press lhaving a rigid U-shaped frame l2 with a base 14 and upwardly extendingsides 16 and 18, between which elements of the press are mounted. Asmore fully shown in FIG. 3, the elements include: a web cassette 20which carries an ink web 22; a plate cylinder 26 adapted to receive animage carrier 28, for example, a conventional aluminum press-plate or apress-plate derived from high speed self-developing film; a dampeningcylinder 30 having a water absorbant surface 32 of blotting papermaterial or the like; a blanket cylinder 34 having a resilient blanket36 of rubber or the like; an impression cylinder 38, and a supply roll40 carrying a continuous length of suitable print-receiving material 42such as a strip of printing paper `or the like.

The cassette 20 is supported in frame l2 by a support member 44, with anexposed web portion 45 in contact with plate cylinder 26. The cylinders26, 30, 34, 38 and 40 are mounted within frame 12 on shafts extendedbetween sides 16 and 18, for rotation of the cylinders about spacedparallel axes in a conventional arrangement for offset printing. Hence,the dampening cylinder 30 and the blanket cylinder 34 are disposed inperipheral contact with the plate cylinder 26; and the impressioncylinder 38 is mounted adjacent the blanket cylinder with the printingmaterial 42 extending between them such that during revolution of theplate cylinder in a counterclockwise direction, when viewed from theleft side of the press as shown in FIG-3, the press-plate 28 issequentially contacted by the dampening surface 32, the ink web portion45 and the blanket 36.

A manual drive is preferred because it is suited to the relatively smallprintingruns intended and to the minimum bulk, weight, and cost factorsdesired. However, an electric motor or other power means can be employedfor this purpose. Preferably, the plate cylinder 26 is driven by meansof a hand crank 46 which is affixed tothe plate cylinder shaft 48. Uponturning of the hand crank 46, the cylinders are rotated and the tapedriven in the directions indicated by the arrows as provided by aplurality of intermeshing gears or by frictional contact of the cylindersurfaces with one another or with printing material 42.

The gears, mounted at the end of their respective cylinders, are ofproper diameter enabling a 1:1 drive ratio between the rotatingcylinders. The gears comprise a drive gear 50 which is afixed to theplate cylinder 26 and which engages a blanket gear 52 and a cassettegear 56. In this embodiment, the impression cylinder 38 also carries agear 58 which engages blanket gear 52 so as to draw the printingmaterial 42 between the impression cylinder and the blanket cylinder34.. However, it should be understood that the printing material may beadvanced by other means, such as conventional rollers or the like (notshown), in which case the impression cylinder may be free-wheeling.Moreover, other impression means may be employed, such as a stationarylow-friction surface or a travelling bed, or the like.

As is more fully explained with regard to the cassette description, thecassette gear is of smaller diameter than the other gears so as toprovide a higher gear ratio, for example 3:1, which, in conjunction withthe changing diameter of the convolute winding and a clutch arrangement,drives the web at a constant speed equal to the motion of thepress-plate, and substantially eliminates slippage between the web andthe press-plate.

In` the preferred embodiment, the cassette is a tworeel unit, shown moreclearly in FIG. 4, in which a pair of housing members 62 and 64 arejoined together to form housing 24 having openings 66 on each sidethereof which define a passage 67 extending laterally through thecassette. A supply spool or reel 68 and a take-up spool or reel 70 arecoplanarly mounted on either side of the openings for rotation aboutparallel axes. The pre-inked web 22 is initially coiled on the supplyreel with the web ends affixed to both, such that the web extendslengthwise across the passage 67 and may be driven from one reel to theother past both of the openings 66. Shafts 72 and 74 extend from therespective reels through an end wall of the housing to permit access forcoupling of either reel to cassette gear 56 which is rotatably mountedwithin frame l2. Disposed on each shaft, between it and the housingwall, are spring washers 73 which exert a light frictional drag on thereels to prevent web slack.

The reels 68 and 70 are mounted on either side of passage 67 such thatthe lateral axis of the web 22 is always substantially normal to thecenter line of the passage whereby the major surfaces of the web may beadvanced across the openings 66. The shafts 72 and 74 are extended fromone side of the cassette 24, the web 22 is wound in opposite directionsaround 'the reels, and the housing is externally configured such thatthe cassettte is symmetrical about the plane which extends between thereels and bisects the passage. Consequently, the cassette may bereversed in its support 44 for printing from the opposite side of theweb during rewinding to the initial supply reel 68. That is, the web maybe reversibly transported across the passage in either direction with aparticular surface exposed for inking of the press-plate in accordancewith whichever reel is driven in a take-up direction. Hence, in actualuse, the cassette may be reversed several times to drive the web backand fourth until the ink is substantially depleted from both sides ofthe web. Advantageously, the convolute winding of the web redistributesthe ink on both sides of the web during each printing run.

The cassette is supplied in a sealed condition, for example, within ahermetically sealed package (not shown) of plastic or the like, and isalso fitted with sealing covers 69 for sealing the openings 66. Sealingmeans can also be included around shafts 72 and 74. For example, washers73 may be of gasket material or the like. Additionally, covers 69 mayinclude gasket material or hermetically sealing the unit.

Web 22, a portion of which is shown in section in FIG. 5, is a flexible,thin strip 75 having surface coatings 76 of suitable ink. Preferably,the strip is a substantially inelastic material which is wettable withthe ink but substantially chemically inactive therewith, and the ink ispreferably a nonskinning ink which dries or becomes nonliquid uponpartial absorption in the print paper. That is, the ink includes adrying inhibitor or anti-skinning agent which retards the action of inkdriers. For example, small amounts of so-called antioxidants of thephenolic or oxine type, such as Hydroquinone or 2-butanone oxine,suitably delay drying of the ink until removal of the inhibitor by, forexample, its absorption into the print-receiving material. That is, theinhibitor permeates the porous surface of the print-receiving materialand consequently permits drying of the ink which remains on the exteriorsurface. For example, a nonskinni'ng ink such as Rubber Base Plus madeby Van- Son Holland Inc. is suitable. Consequently, in the preferredembodiment, the web strip is of material which is substantiallyimpervious to the ink and is made, for example, of a polyester such aspolyethyleneteraphthalate film or the like. It should be understood,however, that other web materials, including woven fiber materials, andmore conventional printing inks may also be employed. The ink may bedeposited on the strip by any numberof means, such as by brushing,spraying, dipping, rolling, or slot coating; and, since the web isconvolutely wound in this embodiment, the ink may be initially spread ononly one of its major surfaces. The ink may be preworked andpreprocessed prior to coating of the strip or reworked after deposition,for example, by rolling or winding the strip, etc. In all cases, the inkis preprocessed before final packaging to a consistency suitable forimmediate application to a press-plate.

As shown in FIG. 3, cassette is designed to fit within the cradle-likesupport member 44 and is releasably secured thereinvby spring members 76which hold the cassette firmly seated. Rotatably mounted on an extendedarm 80 of support member 44 is an inking pressure roller 78 which isadapted to fit within the passage 67 such that, upon mounting thecassette, its web 22 is forced slightly out of opening 66 and exposedfor facilitating transfer of the ink therefrom. Hence, the open endedpassageway 67 'and roller 78'cooperate to provide means for exposingincremental sections of the web exteriorly of the housing. Arm 80 isspring mounted in a conventional manner on spring 81 to provideresilient bias of the web against plate cylinder 26.

The support member 44 is displaceably mounted in the frame l2 tofacilitate insertion and removal of the cassette. To accommodate this,member 44 is pivotably mounted on a shaft.82 at its lower end and islocked by .a latch member 84 at its upper'end so as to allow the supportto be swung out of the frame, as shown at 85.

Cassette 20 and its extended shafts 72 and 74 are automatically coupledto cassette gear 56 when the support member 44 ispivoted to its lockedposition, and as shown more clearly in FIGS. 6 and 7, the latch member84 cooperates with a release member 86 to decouple the cassette gear 56simultaneous with the 'unlatching of support 44. Hence, the shaft 74 ofthe takeup reel 70 is adapted to engage a coupling 88 which extends froma conventional slip cluch 90, mounted on gear 56. Hence, the gear 56 andthe coupling 88 provide an external force applying member for drivingthe web. The coupling is biased toward the cassette support 44 by aspring 92 and is tapered at its outer extremity 94 so that it isinitially moved or driven toward gear S6 by the end of shaft 74, andthen drops into position on the shaft as the support member is locked inits operating position. For release of the drive arrangement, thecoupling member 88 is laterally withdrawn from engagement with the shaftby the release member 86 in response to downward movement of the inwardend 96 of the latch. The latch 84 is pivotally mounted as at 98 andspring biased to a horizontal position for engagement with the shaft 83of the support member 44 such that lifting of its outwardly extended end100, release the support member and simultaneously disengages thecoupling 88.

.To avoid smearing, during plate inking it is desirable to drive web 22at a constant speed approximately in synchronism with the press-plate28. That is, although some motion of the web relative to the press-plateis permitted, for example, slight lateral motion of the web responsiveto its being driven between the inking pressure roller and platecylinder in pressure contact therebetween provides `for additionalredistribution of the ink and varies the ink surface-exposed to thepressplate, it is preferable that the web be driven substantially at thesame linear velocity as the press-plate 28. This necessitates a variablerate of rotation for the take-up reel in accordance with changingdiameter of the convolute winding. To accomplish this, the cassette gear56 is rotated at a rate appropriate to drive the belt at the desiredspeed when the take-up spool holds a minimum of web windings, and clutchappropriately slips as the winding diameter increases. In this regard,the slip clutch 90 is preset to slip under a given load such that, incooperation with spring washers 73 which provide drag on the reels, itapplies substantially constant web tension and, consequently, constantweb speed. Hence, as the take-up diameter increases, with increasedwinding, the drag and web tension tend to increase proportionately suchthat the clutch slips and belt speed remains constant.

In the preferred embodiment, the ink web is affixed to both reels of thecassette, and transported therebetweeh by rotation of at least one ofthe reels. However, many other arrangements are possible; for example,an endless web driven by an engaging sprocket or frictional drive rolleror the like, may be employed. Moreover, the means for advancingthe webmay be separate from the reels, and external to the cassette Forexample, the web may be advanced by pressure contact or other engagement(eg, vsprocket-typel engagement) with the plate cylinder. The inkingpressure roller may also be driven to advance the web.

In another embodiment, a single spool cannister as shown in FIG. 8 isutilized. Herein, web 22 is enclosed within a substantially cylindricalcasing 104, constructed of two members 106 and 108 joined together atoutwardly extending flanges 1 10, which also provide extended lipportions 1 12 and 113 for dispensing of the web. As shown in FIGS. 9and` 10, web 22 is convolutely wound within the casing on a single reell 14 with a leader 116 extending between lips 112 and 113. A shaftportion 1 18 of the spool extends through an opening 120 at one or bothends ofthe casing and provides access for connecting an external driveto the unit. Sealing means, such as an O-ring 122 of leather or thelike, is also provided between the ends of thereel 114 and the casing104 so as to seal the openings and retard ink drying. Preferably, lips112 and 113 are formed so as to be biased toward onel another andclosely press against the web vdisposed therebetween. A portion 124 ofthe lower lip 112 is extended slightly outward beyond the upper lip 113to provide leverage for displacing of one lip from the other so as tofacilitate dispensing of the web. For example, the press may be designedto include a cam means (not shown) to open the lips means ofspring-loaded shafts or the like which engage the ends of the cassetteshaft. Leader 116 is then drawn from the cassette, passed between asuitable inking pressure roller and plate cylinder 26, and attached to atake-up shaft or spool (not shown) by means of fastening loop 126 suchthat, during press operation, the web is drawn from the cassette andstored on the takeup spool. For reuse or disposal of the web, shaft 118is then utilized to drive the supply spool of the cassette in thereverse direction and to rewind the web within the cassette. Forexample, a separate crank could be employed to drive the supply spool ina reverse direction, or, with suitable gearing, the described crankdrive could be reversed in direction for rewinding of the web, etc.

ln this embodiment, the web is permanently affixed at itsinner end tothe supply reel. However, it should be understood that the web could bereleasably mounted and completely drawn from cassette 104 into a similarcassette for disposal. For example, the web may be releasably affixed tothe supply spool, and cassette sections could be so designed as topermit opening of the cassette after exhaustion of the ink material foruse of the empty unit as a take-up cassette in the future operation. y

Those faimilar with the printing arts will readily appreciate the noveland highly unique advantages of this invention. A simple, inexpensiveinking storage and applicator system is provided which facilitates rapidlithographic reproduction. This unique inking system is particularlywell-suited for incorporation into a compact cassette which facilitatesclean, efficient handling of the inking material and permits rapidstartup and efficient intermittent use of the printing apparatus. Mostimportantly, it provides a clean, disposable source of ink of properprinting consistency suitable for the amateur printer and includes asimple and efficient means for applying the ink to the press-plate.

This invention may be practiced or embodied in still other ways withoutdeparting from the spirit or essential character thereof. The preferredembodiment described herein is, therefore, illustrative and notrestrictive, the scope of the invention being indicated by the appendedclaims, and all variations which come within the meaning of the claimsare intended to be embraced therein.

What is claimed is:

1. A cassette for use in printing apparatus adapted to effect the inkingof a press plate housed therein and the transfer of an ink impressionthereof to printing material, such apparatus having inking pressuremeans configured to extend within a cassette housing for support of anink web retained therein, said cassette comprislng:

a generally enclosed housing configured to be releasably mounted in suchprinting apparatus, said housing including a pair of opposed sidewallsjoined together by at least one end wall, said housing including a firstand a second storage area and a passageway interposed between saidstorage areas, said passageway extending between said sidewalls andterminating in an opening in each of said sidewalls;

an ink web including an elongated strip carrying printing ink of aconsistency suitable for application to such press plate, said webdisposed within said housing and initially substantially entirelylocated in said first storage area thereof with a portion of said webextending within said housing across said passageway to said secondstorage area such that an incremental section of one side of said webmay be presented at the opening of one of said sidewalls and theopposite side of said web may be presented at the opening in the otherof said sidewalls, and said passageway configured for receiving suchpressure means such that such inking pressure means may be extendedthrough either of said openings and within said passageway so as tosupport an incremental section of said web at the other of saidopenings; and

means configured for cooperating with drive means of such apparatus forprogressively advancing said ink web from said first to said secondstorage area and across said passageway thereby progressively presentingincremental sections of a given side of said ink web at said otheropening for inking of such press plate.

2. The cassette of claim l additionally including a cover memberconfigured to conform to said openings for sealing the latter.

3. The cassette of claim l wherein said strip is substantiallyimpervious to said ink and the latter is carried as a thin surfacecoating of at least one major surface of said strip.

4. The cassette of claim l wherein said strip is an organic polymer andsaid ink includes a drying inhibitor.

5. A cassette for use in printing apparatus adapted to effect the inkingof a press plate housed therein and the transfer of an ink impressionthereof to printing material, comprising:

a substantially enclosed housing configured to be releasably mounted insuch printing appartus, said housing including a pair of opposedsidewalls joined together by at least one end wall to form a unitaryhousing, each of said sidewalls carrying an opening therein; l

a pair of spools rotatably mounted within said housing to either side ofsaid openings and configured for rotation around axes substantiallyparallel to each other and said sidewalls;

an ink web including an elongated strip carrying a printing ink of aconsistency suitable for application to such press plate, said ink webcoupled at its ends to said spools respectively and extending withinsaid housing across said openings so as to present an incrementalsection of opposite sides of said ink web thereat; and

means coupled to at least one of said spools for cooperating'with drivemeans of such apparatus for rotating said one spool so as toprogressively advance said ink web across said openings therebyprogressively presenting incremental sections of the opposite sides ofsaid ink web at said openings.

6. The cassette of claim 5 wherein such coupling means includes meanscoupled to each of said spools for cooperating with drive means of suchapparatus for rotation of either of said spools, and said housing issymmetrical around at least one of the major axes of said housing suchthat said cassette may be reversibly mounted in such apparatus forreversible transport of said web within said housing and utilization ofboth opposite sides of said web for printing operations.

7. The invention of claim for use in printing apparav tus having inkingpressure means configured to extend within a cassette for support of anink web retained such pressure means such that such inking pressuremeans may be extended through either of said openings and within saidpassageway so as to support an incremental section of said web at theother of said openings and thereby present an incremental section of agiven side of -said web at said other opening.

8. The cassette of claim 7 wherein said web extends from one side of afirst of said spools to the opposite side ofthe second of said spoolssuch that the longitudinal axis of the portion of said web within saidpassageway extends angularly thereacross so that such portion issubstantially equidistant from either of said openings.

1. A cassette for use in printing apparatus adapted to effect the inkingof a press plate housed therein and the transfer of an ink impressionthereof to printing material, such apparatus having inking pressuremeans configured to extend within a cassette housing for support of anink web retained therein, said cassette comprising: a generally enclosedhousing configured to be releasably mounted in such printing apparatus,said housing including a pair of opposed sidewalls joined together by atleast one end wall, said housing including a first and a second storagearea and a passageway interposed between said storage areas, saidpassageway extending between said sidewalls and terminating in anopening in each of said sidewalls; an ink web including an elongatedstrip carrying printing ink of a consistency suitable for application tosuch press plate, said web disposed within said housing and initiallysubstantially entirely located in said first storage area thereof with aportion of said web extending within said housing across said passagewayto said second storage area such that an incremental section of one sideof said web may be presented at the opening of one of said sidewalls andthe opposite side of said web may be presented at the opening in theother of said sidewalls, and said passageway configured for receivingsuch pressure means such that such inking pressure means may be extendedthrough either of said openings and within said passageway so as tosupport an incremental section of said web at the other of saidopenings; and means configured for cooperating with drive means of suchapparatus for progressively advancing said ink web from said first tosaid second storage area and across said passageway therebyprogressively presenting incremental sections of a given side of saidink web at said other opening for inking of such press plate.
 2. Thecassette of claim 1 additionally including a cover member configured toconform to said openings for sealing the latter.
 3. The cassette ofclaim 1 wherein said strip is substantially impervious to said ink andthe latter is carried as a thin surface coating of at least one majorsurface of said strip.
 4. The cassette of claim 1 wherein said strip isan organic polymer and said ink includes a drying inhibitor.
 5. Acassette for use in printing apparatus adapted to effect the inking of apress plate housed therein and the transfer of an ink impression thereofto printing material, comprising: a substantially enclosed housingconfigured to be releasably mounted in such printing appartus, saidhousing including a pair of opposed sidewalls joined together by atleast one end wall to form a unitary housing, each of said sidewallscarrying an opening therein; a pair of spools rotatably mounted withinsaid housing to either side of said openings and configured for rotationaround axes substantially parallel to each other and said sidewalls; anink web including an elongated strip carrying a printing ink of aconsistency suitable for application to such press plate, said ink webcoupled at its ends to said spools respectively and extending withinsaid housing acroSs said openings so as to present an incrementalsection of opposite sides of said ink web thereat; and means coupled toat least one of said spools for cooperating with drive means of suchapparatus for rotating said one spool so as to progressively advancesaid ink web across said openings thereby progressively presentingincremental sections of the opposite sides of said ink web at saidopenings.
 6. The cassette of claim 5 wherein such coupling meansincludes means coupled to each of said spools for cooperating with drivemeans of such apparatus for rotation of either of said spools, and saidhousing is symmetrical around at least one of the major axes of saidhousing such that said cassette may be reversibly mounted in suchapparatus for reversible transport of said web within said housing andutilization of both opposite sides of said web for printing operations.7. The invention of claim 5 for use in printing apparatus having inkingpressure means configured to extend within a cassette for support of anink web retained therein, and wherein said cassette housing includes apassageway extending between said spools and terminating in saidopenings in each of said sidewalls, said ink web extends across saidpassageway such that one side of said web may be presented at theopening in one of said sidewalls and the opposite side of said web maybe presented at the opening in the other of said sidewalls, and saidpassageway is configured for receiving such pressure means such thatsuch inking pressure means may be extended through either of saidopenings and within said passageway so as to support an incrementalsection of said web at the other of said openings and thereby present anincremental section of a given side of said web at said other opening.8. The cassette of claim 7 wherein said web extends from one side of afirst of said spools to the opposite side of the second of said spoolssuch that the longitudinal axis of the portion of said web within saidpassageway extends angularly thereacross so that such portion issubstantially equidistant from either of said openings.